The present invention relates to particulate, wax-containing composite materials (“wax composites” or “wax nanocomposites”), in particular in the form of inorganic-organic hybrid composite materials, and to a process for preparing them, and to the use thereof.
The present invention relates more particularly to inorganic-organic composite particles, in particular composite nanoparticles, the composite particles comprising at least one organic-based material, which comprises or consists of at least one wax, and an inorganic-based material, and to a process for preparing them, and to the use thereof.
The present invention further relates to the use of these composite particles, in particular in coating materials and coating systems, such as, in particular, paints, inks, and the like, in dispersions of all kinds, in plastics, in foams, in cosmetics, in particular nail varnishes, in adhesives, in sealants, etc.
The present invention relates, furthermore, to the use of these composite particles as fillers or ingredients, in particular in the aforementioned systems.
The present invention finally relates to such systems, in particular coating materials and coating systems, such as, in particular, paints, inks, and the like, plastics, foams, and cosmetics, such as, in particular, nail varnishes, which comprise these composite particles.
Additionally provided by the present invention are innovative dispersions which comprise these composite particles in a carrier medium or dispersion medium.
In order to improve the mechanical properties of coating systems and dispersion systems (including, for example, paints, inks such as printing inks, coatings) and of plastics, in particular, specifically, for increasing their wear properties, such as scratch resistance and abrasion resistance, the incorporation of additives and fillers, such as, for example, of waxes or inorganic filler particles (e.g., of what are called nanoparticles), is known in principle to the skilled person.
The inorganic filler particles known from the prior art do indeed, under certain circumstances, improve the scratch resistance of the coating systems (e.g., of paints), in which they are used; however, following application, there may be increased brittleness of the resulting coating film (e.g., of a paint film). In addition, the incorporation of these filler particles often results in unwanted clouding and deficient transparency of the coating system. In addition, relatively high filler contents are frequently necessary in order to achieve the desired effects, and this makes it more difficult to stabilize the resulting dispersion systems, and is also undesirable on cost grounds.
WO 2007/072189 A2 relates to a silylated polymer emulsion which further comprises nanosilicate, and to its use for coating systems. With the emulsions described therein, however, it is not always possible to obtain the desired performance properties.
EP 0 960 871 A2 relates to aqueous preparations for treating mineral construction materials, the aqueous preparations comprising, in addition to an emulsion of a polyfunctional carbosilane and/or condensation product thereof, an emulsion of an organopolysiloxane, and a water-dispersible or water-emulsifiable organic polymer, inorganic nanoparticles in addition.
JP 07138484 A relates to the production of extrudates from a mixture of wax, oils or resins and a pulverulent inorganic material, such as talc or silica, for example. The incorporated additional components are said to have effects including an improved flow capacity in the extrusion operation with the wax.
JP 06166756 A relates to emulsions of finely divided wax particles having particle diameters of 0.1 to 100 μm in an inert liquid, preferably a hydrofluorocarbon, such as perfluoropentane, using hydrophobic silica as emulsifier in amounts of 1 to 20 parts by weight per 100 parts by weight of wax. The hydrophobized silica, which is employed solely as an emulsifier, is obtained by reacting the surface of hydrophilic silica with a hydrophobizer, in particular halogenated alkylsilane or alkoxysilane.
JP 2004-339515 A relates to the preparation of precipitated silica having surface-modified properties, the silica prepared in this way being intended for use as a matting agent in paints. The surface modification takes place by treatment of the silica surface with a polyethylene wax, resulting in wax-coated silica particles.
KR 10-2004-0098585 A relates to precipitated silica whose surface is coated with a polyorganosiloxane polymer, and also to a process for producing it. The surface-modified silica is intended to be used as a matting agent for transparent coating materials.
Furthermore, KR 10-2005-0094496 A relates to a preparation process for a core/shell polymer latex, in order to improve the degree of coupling between wax particles and latex particles and in that way to simplify the preparation procedure, by removing the need to prepare a wax emulsion beforehand. The preparations prepared in this way are intended to serve as toner compositions for electrophotographic image apparatus, in particular copiers.
WO 95/31508 A1 relates to wax-coated silica particles which are to be used as matting agents.
Furthermore, EP 1 182 233 B1 relates to a method of covering silicas with waxes, the intention being that the silicas described therein should find use as matting agents in paints.
EP 1 204 701 B1 relates to a cured coating on a substrate, featuring a concentration gradient of the filler particles present in the coating such that, within regions of the coating that are close to the surface, the concentration of the incorporated filler particles is greater than the concentration of these particles within the regions of the coating situated beneath. As a result of this, however, because of inhomogeneity in the coating, an improvement is achieved which is only regional, exclusively in the region of the surface.
US 2006/0228642 A1, finally, relates to a process for preparing polymer latex particles with core/shell structure, having an inner wax core and an outer latex shell, the intention being that such particles should be usable in particular for toner compositions.
Wax-containing composite particles for improving the mechanical properties of coating systems, in particular for increasing the wear resistance, have not yet been proposed to date in the prior art.